Posts about Life Science

Biology: How Wounds to Our Skin Heal

This is an interesting webcast looking at how our bodies heal wounds to our skin.

Related: Science Explained: How Cells React to Invading VirusesTissue Regeneration in AnimalsScience Explained: Cool Video of ATP Synthase, Which Provides Usable Energy to UsLooking Inside Living CellsA Healthy Lifestyle is More About Health Care than the Sickness Management That We Call Health Care Is

Deinocheirus is a Totally Bizarre Dinosaur

A very strange dinosaur has been uncovered, studied and explained by scientists. The dinosaur is from Mongolia about 70 million years ago.

“Deinocheirus is a totally bizarre dinosaur,” explains Phil Currie, professor and Canada Research Chair in Dinosaur Paleobiology at the University of Alberta. At 11 meters long and with an estimated weight of 6.4 tons, Deinocheirus was a behemoth to be sure—but hardly the giant tyrannosaur its massive arms may have suggested. Rather, the apparently disproportionately large forearms were more likely used for digging and gathering plants in freshwater habitats, or for fishing. Among its other unusual attributes are tall dorsal spines, truncated hoof-like claws on the feet to prevent sinking into muddy ground, and bulky hind legs that indicate it was a slow mover.

“Although the arms have been known since 1965 and have always aroused speculation because of their enormous size and sharp, recurving claws, we were completely unprepared for how strange this dinosaur looks,” says Currie. “It almost appears to be a chimera, with its ornithomimid-like arms, its tyrannosaurid-like legs, its Spinosaurus-like vertebral spines, its sauropod-like hips, and its hadrosaur-like duckbill and foot-hooves.”

Currie notes that Deinocheirus is a descendant of ostrich-like dinosaurs that were only slightly larger than humans, so its evolution into a giant, multi-tonne creature is almost certainly responsible for most of its unusual characteristics. “Its great size probably gave it some protection from the tyrannosaurid Tarbosaurus, which appears to have been relatively common in that part of Mongolia some 70 million years ago,” says Currie. To feed its great bulk, Deinocheirus was apparently an omnivore that ingested both plants and fish, as evident from fish remains found in its stomach contents.

“The study of this specimen has shown that even in dinosaurs like Deinocheirus, an animal that has been known for almost half a century, we can still learn surprising things about their anatomy,” says Currie. “Furthermore, it underlines the fact that even today, dinosaurs are still relatively poorly known. The fact that Deinocheirus is from the Nemegt Formation of Mongolia, one of the richest and most diverse dinosaur faunas known, hints that there are probably thousands of dinosaurs that we still do not know about from the majority of dinosaur localities in the world.”

Including poached dinosaur bones (stealing bones has long been a problem to the advancement of science) with the existing bones available to scientists allowed the new understanding of this amazing dinosaur. The now near-complete Deinocheirus specimen has been returned to its home for further study in the Mongolia Centre for Paleontology.

Full press release

Related: Ancient Whale Uncovered in Egyptian DesertNigersaurus, the Mesozoic CowDinosaur Remains Found with Intact Skin and TissueLobopodians from China (“the walking cactus” – an animal)Korea-Mongolia International Dinosaur Project

Apples Increase the Growth of Beneficial Bacteria in Our Guts, Which Improves Our Health

Science provides some very clear knowledge that is easy for us to apply (the value of vaccines, materials to use in solar panels, support needed to build a bridge, dangers of consuming small amounts of lead…). But much of our knowledge about nutrition and human health is a bit unclear. This is one of the struggles we face is using our judgement to decide how to eat and live based on what we know and what seems to be so.

Eating more fruit and vegetables than most in the USA eat is pretty clearly beneficial to our health. but exactly how much, how beneficial, how it is beneficial are questions with only varying degrees of good answers so far. Apple’s Scientists at Washington State University have concluded that nondigestible compounds in apples – specifically, Granny Smith apples – may help prevent disorders associated with obesity.

“We know that, in general, apples are a good source of these nondigestible compounds but there are differences in varieties,” said food scientist Giuliana Noratto, the study’s lead researcher. “Results from this study will help consumers to discriminate between apple varieties that can aid in the fight against obesity.”

The tart green Granny Smith apples benefit the growth of friendly bacteria in the colon due to their high content of non-digestible compounds, including dietary fiber and polyphenols, and low content of available carbohydrates. The non-digestible compounds are fermented by bacteria in the colon, which benefits the growth of friendly bacteria in the gut.

The study showed that Granny Smith apples surpass Braeburn, Fuji, Gala, Golden Delicious, McIntosh and Red Delicious in the amount of nondigestible compounds they contain.

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Ocean Exploration – Live Feed and Highlights

Nautilus Live provides a live view of the E/V Nautilus as it explores the ocean studying biology, geology, archeology, and more. The site also includes highlights such as this video of a siphonophore.

Siphonophores are actually made up of numerous animals even though they look like one animal. These amazing colonial organisms are made up up many smaller animals called zooids, and can be found floating around the pelagic zone in ocean basins. The Portugese Man O’ War is a famous siphonophore.

Each zooid is an individual, but their integration with each other is so strong, the colony attains the character of one large organism. Indeed, most of the zooids are so specialized, they lack the ability to survive on their own.

Related: Giant Star Fish and More in AntarcticaHydromedusae, Siphonophora, Cnidarians, Ctenophores (what are jellyfish?)Macropinna Microstoma: Fish with a Transparent HeadLarge Crabs Invading Antarctic as Waters Warm

Here is another video from Nautilus, showing a large dumbo octopus:

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Nutrition and Digestion in Horses

Unlike cattle which have several stomachs (and there own interesting digestion system), horses have only one stomach. Like cattle their natural diet is grass. With feed provided by people, horses can run into issues they don’t experience from their natural diet. Fresh grass is fibrous and slows down digestion. If feed is used the feeding should be spread out several times during the day, due to the horses digestive system.

image of the digestive system of a horse

image via eXtention. The next 4 paragraphs are slightly edited quotes from the link.

The small intestine is the main site of digestion and absorption of protein, energy, vitamins and minerals.

The cecum is located after the small intestine of a horse and it functions much like the rumen of a cow (as a fermentative vat housing microbes which aid digestion). These microbes break down nutrient sources that would otherwise be unavailable to the horse.

The cecum and colon house bacterial, protozoal and fungal populations which function in microbial digestion of feed material in the digestive tract. Many different products of microbial digestion are absorbed by the horse.

Among other benefits, incorporating long-stem forage into rations increases particle size of ingested matter, thus slowing rate of passage. It also increases dry matter intake, thus stimulating water intake.

Nutrients and Common Feed Sources for Horses from the extension service (USA land grant universities)

Carbohydrates provide the majority of a horse’s energy. Non-structural carbohydrates, such as starch and glucose from grains and gums and pectins from fiber, are readily utilized as energy sources for the horse. The enzyme amylase breaks down non-structural carbohydrates into glucose and simple sugars, which are absorbed in the small intestine.

Structural carbohydrates, such as cellulose and hemicellulose in plants, can only be broken down by bacterial enzymes in the cecum and colon. The microorganisms convert these carbohydrates to volatile fatty acids (acetate, propionate, butyrate), which can provide 30 to 70 percent of the horse’s energy requirement.

Fibrous feeds are a very important part of the horse’s diet. They provide nutrients for both the horse and microbes in the hindgut as well as stimulate muscle tone and activity of the gastrointestinal tract.

Mineral supplements are usually required in the horse’s diet. Macrominerals are added to a horse’s diet to balance the ration to meet mineral requirements.

Human raised horses usually have some grazing but get some or much of there food needs from feed. Those feeds often supplement normal food for wild horses with beets, apples, carrots and other sources. In addition the horse food supplements include minerals, fiber and even pre-biotics and pro-biotics (just like our processed food does).

As a general rule, horses need 1 to 2 quarts (2 to 4 liters per kilogram) of water per pound of dry matter consumed. Of course, other factors can increase the water need, such as exercise (since it results in water loss through sweating).

Related: Great Webcast Explaining the Digestive SystemsEnergy Efficiency of DigestionTracking the Ecosystem Within Us

Looking Inside Living Cells

Johns Hopkins’ molecular biologist Jin Zhang explains how she uses light to see where and when within cells specific molecular processes occur and what happens when they go wrong.

Related: How Lysozyme Protein in Our Tear-Drops Kill BacteriaScience Explained: How Cells React to Invading VirusesNobel Prize in Physiology or Medicine 2012 for Reprogramming Cells to be PluripotentWebcast Exploring Eukaryotic Cells

DNA Contains Gene Control Instructions

Scientists discover double meaning in genetic code

Scientists have discovered a second code hiding within DNA. This second code contains information that changes how scientists read the instructions contained in DNA and interpret mutations to make sense of health and disease.

“For over 40 years we have assumed that DNA changes affecting the genetic code solely impact how proteins are made,” said Stamatoyannopoulos. “Now we know that this basic assumption about reading the human genome missed half of the picture. These new findings highlight that DNA is an incredibly powerful information storage device, which nature has fully exploited in unexpected ways.”

The genetic code uses a 64-letter alphabet called codons. The UW team discovered that some codons, which they called duons, can have two meanings, one related to protein sequence, and one related to gene control. These two meanings seem to have evolved in concert with each other. The gene control instructions appear to help stabilize certain beneficial features of proteins and how they are made.

The discovery of duons has major implications for how scientists and physicians interpret a patient’s genome and will open new doors to the diagnosis and treatment of disease.

“The fact that the genetic code can simultaneously write two kinds of information means that many DNA changes that appear to alter protein sequences may actually cause disease by disrupting gene control programs or even both mechanisms simultaneously,” said Stamatoyannopoulos.

The wonder of DNA continues to amaze.

Related: Epigenetic Effects on DNA from Living Conditions in Childhood Persist Well Into Middle AgeDNA Passed to Descendants Changed by Your LifeDNA based Algorithmic Self-Assembly

Outdoor Air Pollution Resulted in 223,000 Cancer Deaths in 2010

The specialized cancer agency of the World Health Organization, the International Agency for Research on Cancer (IARC), announced today that it has classified outdoor air pollution as carcinogenic to humans.

After thoroughly reviewing the latest available scientific literature, the world’s leading experts convened by the IARC Monographs Programme concluded that there is sufficient evidence that exposure to outdoor air pollution causes lung cancer. They also noted a positive association with an increased risk of bladder cancer.

Particulate matter, a major component of outdoor air pollution, was evaluated separately and was also classified as carcinogenic to humans.

The IARC evaluation showed an increasing risk of lung cancer with increasing levels of exposure to particulate matter and air pollution. Although the composition of air pollution and levels of exposure can vary dramatically between locations, the conclusions of the Working Group apply to all regions of the world.

Air pollution is already known to increase risks for a wide range of diseases, such as respiratory and heart diseases. Studies indicate that in recent years exposure levels have increased significantly in some parts of the world, particularly in rapidly industrializing countries with large populations. The most recent data indicate that in 2010, 223,000 deaths from lung cancer worldwide resulted from air pollution.

“The air we breathe has become polluted with a mixture of cancer-causing substances,” says Dr Kurt Straif.

The stories of amazingly high (and persistent) air pollution levels in China have been continuing for years. But, while China, likely represents several of the worst existing air pollution conditions hundreds of thousands have died outside China due to air pollution just in the last 5 years.

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Mechanical Gears Found in Jumping Insects

A natural example of a functioning gear mechanism has been discovered in a common insect – the plant-hopper Issus – showing that evolution developed interlocking cogs long before we did.

The gears in the Issus hind-leg bear remarkable engineering resemblance to those found on every bicycle and inside every car gear-box. Each gear tooth has a rounded corner at the point it connects to the gear strip; a feature identical to man-made gears such as bike gears – essentially a shock-absorbing mechanism to stop teeth from shearing off.

The gear teeth on the opposing hind-legs lock together like those in a car gear-box, ensuring almost complete synchronicity in leg movement – the legs always move within 30 ‘microseconds’ of each other, with one microsecond equal to a millionth of a second.

This is critical for the powerful jumps that are this insect’s primary mode of transport, as even miniscule discrepancies in synchronisation between the velocities of its legs at the point of propulsion would result in “yaw rotation” – causing the Issus to spin hopelessly out of control.

“This precise synchronisation would be impossible to achieve through a nervous system, as neural impulses would take far too long for the extraordinarily tight coordination required,” said lead author Professor Malcolm Burrows, from Cambridge’s Department of Zoology.

“By developing mechanical gears, the Issus can just send nerve signals to its muscles to produce roughly the same amount of force – then if one leg starts to propel the jump the gears will interlock, creating absolute synchronicity.

Interestingly, the mechanistic gears are only found in the insect’s juvenile – or ‘nymph’ – stages, and are lost in the final transition to adulthood. These transitions, called ‘molts’, are when animals cast off rigid skin at key points in their development in order to grow.

It may also be down to the larger size of adults and consequently their ‘trochantera’ – the insect equivalent of the femur or thigh bones. The bigger adult trochantera might allow them to can create enough friction to power the enormous leaps from leaf to leaf without the need for intermeshing gear teeth to drive it, say the scientists.

It’s not yet known why the Issus loses its hind-leg gears on reaching adulthood. The scientists point out that a problem with any gear system is that if one tooth on the gear breaks, the effectiveness of the whole mechanism is damaged. While gear-teeth breakage in nymphs could be repaired in the next molt, any damage in adulthood remains permanent. It is amazing what evolution results in, not only gears but a system that changes to a different solution (maybe, who knows the real “reason”) when the gears solution lack of robustness would create a problem for survivability.

While there are examples of apparently ornamental cogs in the animal kingdom – such as on the shell of the cog wheel turtle or the back of the wheel bug – gears with a functional role either remain elusive or have been rendered defunct by evolution.

Related: Using Bacteria to Power Microscopic MachinesWebcast of a T-cell Killing a Cancerous CellBuilding A Better Bed Bug Trap Using Bean Leaves

In the video above, Professor Malcolm Burrows talks about finding the bugs that led to the science, and working with artists Elizabeth Hobbs and Emily Tracy and members of the community in the London borough of Hackney to produce the film ‘Waterfolk’.

Full press release

Exercise Reduces Anxiety While Also Promoting the Growth of New Neurons

Exercise reorganizes the brain to be more resilient to stress

These findings potentially resolve a discrepancy in research related to the effect of exercise on the brain — namely that exercise reduces anxiety while also promoting the growth of new neurons in the ventral hippocampus. Because these young neurons are typically more excitable than their more mature counterparts, exercise should result in more anxiety, not less. The Princeton-led researchers, however, found that exercise also strengthens the mechanisms that prevent these brain cells from firing.

From an evolutionary standpoint, the research also shows that the brain can be extremely adaptive and tailor its own processes to an organism’s lifestyle or surroundings, Gould said. A higher likelihood of anxious behavior may have an adaptive advantage for less physically fit creatures. Anxiety often manifests itself in avoidant behavior and avoiding potentially dangerous situations would increase the likelihood of survival, particularly for those less capable of responding with a “fight or flight” reaction, she said.

The anxiety-reducing effect of exercise was canceled out when the researchers blocked the GABA receptor that calms neuron activity in the ventral hippocampus.

Interesting research (with mice) that explores how exercise makes us more resilient to stress. I know for me, exercise seems to help relieve stress.

Related: Feed your Newborn NeuronsNew Neurons are Needed for New MemoriesRegular Aerobic Exercise for a Faster Brain (2007)Inactivity Leads to 5.3 Million Early Deaths a YearHow Aerobic Exercise Suppresses Appetite

Europe Bans Certain Pesticides, USA Just Keeps Looking, Bees Keep Dying

For years the bee colony collapse disorder has been showing the difficulty of the scientific inquiry process. And that difficulty often becomes more difficult if interests with lots of money at stake want to block certain conclusions.

One-Third of U.S. Honeybee Colonies Died Last Winter, Threatening Food Supply

Multiple factors — pesticides, fungicides, parasites, viruses and malnutrition — are believed to cause the losses, which were officially announced today by a consortium of academic researchers, beekeepers and Department of Agriculture scientists.

“We’re getting closer and closer to the point where we don’t have enough bees in this country to meet pollination demands,” said entomologist Dennis vanEngelstorp of the University of Maryland, who led the survey documenting the declines.

Beekeepers lost 31 percent of their colonies in late 2012 and early 2013, roughly double what’s considered acceptable attrition through natural causes. The losses are in keeping with rates documented since 2006, when beekeeper concerns prompted the first nationwide survey of honeybee health. Hopes raised by drop in rates of loss to 22 percent in 2011-2012 were wiped out by the new numbers.

Most losses reported in the latest survey, however, don’t actually fit the CCD profile. And though CCD is largely undocumented in western Europe, honeybee losses there have also been dramatic. In fact, CCD seems to be declining, even as total losses mount. The honeybees are simply dying.

“Even if CCD went away, we’d still have tremendous losses,” said entomologist Diana Cox-Foster at Pennsylvania State University. “CCD losses are like the straw that breaks the camel’s back. The system has many other issues.”

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